Storing hydrogen underground could boost transportation, energy security

Large-scale storage of low-pressure, gaseous hydrogen in salt caverns and other underground sites for transportation fuel and grid-scale energy applications offers several advantages over above-ground storage, says a recent Sandia National Laboratories study sponsored by the Department of Energy’s Fuel Cell Technologies Office.

Geologic storage of hydrogen gas could make it possible to produce and distribute large quantities of hydrogen fuel for the growing fuel cell electric vehicle market, the researchers concluded.

Geologic storage solutions can service a number of key hydrogen markets since “costs are more influenced by the geology available rather than the size of the hydrogen market demand,” said Sandia’s Anna Snider Lord, the study’s principal investigator.

The work, Lord said, could provide a roadmap for further research and demonstration activities, such as an examination of environmental issues and geologic formations in major metropolitan areas that can hold gas. Researchers could then determine whether hydrogen gas mixes with residual gas or oil, reacts with minerals in the surrounding rock or poses any environmental concerns.

Storage seen as key to realizing hydrogen’s market growth

Should the market demands for hydrogen fuel increase with the introduction of fuel cell electric vehicles, the U.S. will need to produce and store large amounts of cost-effective hydrogen from domestic energy sources, such as natural gas, solar and wind, said Daniel Dedrick, Sandia hydrogen program manager.

As Toyota, General Motors, Hyundai and others move ahead with plans to develop and sell or lease hydrogen fuel cell electric vehicles, practical storage of hydrogen fuel at large scale is necessary to enable widespread hydrogen-powered transportation infrastructure. Such storage options, Dedrick said, are needed to realize the full potential of hydrogen for transportation.

Additionally, installation of electrolyzer systems on electrical grids for power-to-gas applications, which integrate renewable energy, grid services and energy storage will require large-capacity, cost-effective hydrogen storage.

Storage above ground requires tanks, which cost three to five times more than geologic storage, Lord said. In addition to cost savings, underground storage of hydrogen gas offers advantages in volume. “Above-ground tanks can’t even begin to match the amount of hydrogen gas that can be stored underground,” she said.

The massive quantities of hydrogen that are stored in geologic features can subsequently be distributed as a high-pressure gas or liquid to supply hydrogen fuel markets.

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